• 제목/요약/키워드: Dual process

검색결과 997건 처리시간 0.027초

산업환경시설의 설계하중과 내진성능목표 개선안 (Improvement in Design Load and Seismic Performance Objective for Industrial and Environmental Facilities)

  • 김익현;홍기증;김정한;이진호;조성국;이진형
    • 대한토목학회논문집
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    • 제42권6호
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    • pp.763-773
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    • 2022
  • 산업환경시설은 국가 성장동력 지원시설로서 자연재해에 의한 하중을 포함한 다양한 하중 조건에 대해서 구조적 안전성을 확보해야 하며 그 공정을 유지하여 생산활동을 지속하는 것이 매우 중요하다. 이 연구에서는 구조적 안전성을 확보하기 위한 기존 국내외 구조 및 내진설계기준을 개선하여, 산업환경시설의 구조적 안전성 확보와 설비의 운전성 유지를 위한 설계기준을 제안하고자 한다. 이 설계기준에서는 산업환경시설의 특성을 반영하여 다양한 하중을 고려하고, 구조설계를 위해 강도설계법과 허용응력설계법의 하중조합을 제시한다. 산업환경시설의 내진설계를 위해, 단위산업시설 중요도와 단위공정 중요도에 따른 단위공정의 내진등급, 설계지진 수준 및 내진성능수준을 설정하여 산업환경시설의 이원화된 내진성능목표를 달성하고자 한다. 더불어, 대표적인 예제 산업환경시설을 선정하여 새로운 구조 및 내진설계기준의 적용성을 검토한다.

조선족 아르바이트 유학생의 차별경험 - Colaizzi의 현상학적 연구방법 접근 - (Experience of Korean-Chinese Part-time Job Students in Korea - Approach to the Phenomenological Research Method of Colaizzi-)

  • 정림;최원규
    • 문화기술의 융합
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    • 제9권1호
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    • pp.267-279
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    • 2023
  • 본 연구는 조선족 아르바이트 유학생의 차별경험과 의미를 알아보고자 한다. 이를 위해 조선족 아르바이트 유학생 9명을 대상으로 2022년 5월부터 6월까지 심층면담 후 자료를 Colaizzi의 현상학적 연구방법으로 분석하였다. 연구결과는 다음과 같다. 첫째, 생활비 마련과 효율적인 적응을 위한 새로운 도전, 둘째, 가시덤불 가득한 이 길, 셋째, 차별을 넘는 적응에 노력, 넷째, 아르바이트를 통한 성장과 관계맺음에 기회로 드러났다. 이 경험은 조선족 아르바이트 유학생에게 경제적인 문제를 해결뿐만 아니라 자신이 더 성장하는 과정이 되었다. 그러나 그들은 유학생과 조선족인 이중신분으로 다중차별을 받고 있다. 그들의 조선족 신분은 아르바이트 과정에서 더 지향적인 차별경험을 준다. 하지만 이 과정에서 그들은 어려움을 극복하고 있다. 조선족 유학생은 차별경험을 받아드리고 유학생활에 적응하며 성장하고 있다. 이상의 연구결과로 우리는 향후 다문화사회의 발전으로 조선족 아르바이트 유학생의 근로인권보장의 교육과 도움이 필요하다.

설계수명 이후 해체를 위한 금속 겸용용기의 방사화 특성 평가 (Activation Analysis of Dual-purpose Metal Cask After the End of Design Lifetime for Decommission)

  • 김태만;구지영;도호석;조천형;고재훈
    • 방사성폐기물학회지
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    • 제14권4호
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    • pp.343-356
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    • 2016
  • 한국원자력환경공단에서는 국내 경수로 원전에서 발생한 사용후핵연료를 건식으로 저장하기 위하여 안전성을 최우선으로 국내/외 기술기준을 준수하여 금속겸용용기를 개발하였다. 이러한 금속용기는 50년 동안 주요 안전성요소(구조, 열제거, 격납, 임계방지, 방사선차폐 등)에 대한 건전성을 유지하고, 운영기간 중 유지보수 과정에 폐기물의 발생을 최소화 하고 이를 안전하게 관리할 수 있도록 설계하였다. 본 논문은 설계수명이 종료된 금속용기 본체 및 내/외부 구조물에 대한 방사화 평가를 통해 정량적인 방사능 재고량에 대한 정보를 제공한다. 본 논문에서는 금속용기 본체 및 구성품의 방사화 방사능 재고량은 MCNP5 ORIGEN-2 평가체계를 이용하여 계산하였으며, 각 구성품의 화학조성, 중성자속 분포, 반응률 및 저장기간 동안 중성자조사 기간을 반영하여 평가하였다. 평가결과, 설계수명 이후 10년 경과시 모든 금속재질에서 $^{60}Co$의 방사능이 기타 핵종들에 비하여 가장 큰 방사능을 띄는 것으로 나타났으며, 중성자차폐체인 수지에서는 수명직후 $^{28}Al$$^{24}Na$등의 고에너지 감마선을 방출하는 핵종은 반감기가 짧아 0.5년 이후에는 무시할 수 있는 수준으로 나타났다. 또한, 사용후핵연료 제거후 캐니스터 및 금속용기 본체에 대한 표면 선량률 평가결과, 상당히 낮은 값을 나타내어, 해체 시 작업자가 받는 피폭선량은 무시할 수 있는 수준으로 평가되었다. 본 평가방법은 사용후핵연료 금속겸용용기 해체 시 계획의 수립 및 해체작업 종사자의 피폭선량 예측, 방사성폐기물의 관리/재활용 등의 기본자료로 활용할 수 있을 것으로 사료된다.

페인트 도장공사의 색관리에 관한 연구 (A study on the color controlled of painter's work)

  • 심명섭;이현정
    • 한국건축시공학회지
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    • 제3권1호
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    • pp.107-114
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    • 2003
  • This study aims to find methods that prevents aging of buildings paint coating and that limits defects in construction. Defects in painting can occur in four stages: pure paint, during painting, after the paint coating has dried, and after some period of time has passed after coating. Paint may become bad due to precipitation of pigments, formation of membranes, and seeding during manufacturing. Therefore, it is important that the paint is well mixed and kept airtight at a cool, dark place. Indents, paint brush strokes, orange peel, separation of colors, and paint running and spreading during the paint work process can be prevented by using high quality materials and applying a high-level of construction method. After the paint coating has dried, boiling, yellowing, poor drying, poor bonding, and/or glen deficiency may occur. These are influenced by the levels of cleanness of the dried product, drying temperature and hydration. Then, when the coating has been left dried for some period of time, cracking, peeling, scaling, swelling, discoloring, and/or rusting may develop due to the ultraviolet and contaminants in the air. Since these defects occur due to inappropriate construction schedule and/or hot and humid condition, one must use weatherproof materials. Furthermore, poor paint color may be caused by contamination in the sample plate, discoloration, and/or discrepancies in colors which are due to material differences, level of glossiness, degree of dispersion, dual color property of metallic colors, precipitation of pigments, etc. One should achieve reduction in construction cost and effectiveness in paint work by limiting contaminations in the construction site and strictly observing to construction regulations.

3차원 안면자동인식기의 Positioning 오차분석 (An Positioning Error Analysis of 3D Face Recognition Apparatus)

  • 곽창규;조용범;손은혜;유정희;고병희;김종원;김규곤;이의주
    • 사상체질의학회지
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    • 제18권2호
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    • pp.34-40
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    • 2006
  • 1. Objectives We are going to develope 3D Face Recognition Apparatus to analyse the facial characteristics of the Sasangin. In the process, we should identify the recognition rate of the three dimensional position using this Apparatus. 2. Methods We took a photograph of calibrator($280{\times}400mm$) with interval of 20mm longitudinal direction of 10 times using 3D Face Recognition Apparatus. In the practice, we obtained 967 point to the exclusion of points deviating from the visual field of dual camera. And we made a comparison between measurement values and three dimensional standard values to calculate the errors. 3. Results and Conclusions In this test, the average error rate of X axis values was 0.019% and the maximum error rate of X axis values was 0.033%, the average error rate of Y axis values was 0.025% and the maximum error rate of Y axis values was 0.044%, the average error rate of Z axis values was 0.158% and the maximum error rate of Z axis values was 0.269%. This results exhibit much improvement upon the average error rate 1% and the maximum error rate 2.242% of the existing 3D Recognition Apparatus. In conclusion, we assessed that this apparatus was adaptable to abstract the facial characteristic point from three dimensional face shape in the mechanical aspects.

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공공기관의 정보보안 관리 모델 연구 (Study of Information Security Management Model in Public Institution)

  • 김재경;정윤수;오충식;김재성
    • 디지털융복합연구
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    • 제11권2호
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    • pp.43-50
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    • 2013
  • 최근 지능화 고도화 되고 있는 사이버위협으로부터 기업의 정보자산을 안전하게 보호하기 위해서는 기술적인 분야뿐만 아니라 관리적, 환경적 분야 등 전방위적 대응체제를 구축하여야 한다. 본 연구에서는 보안적으로 안전한 망 설계를 위해 물리적 망분리와 논리적 망분리등 보안 망 이론에 대한 사례를 분석하여 기업 환경에 적합하고 상시적 대응 및 관리가 가능한 정보보호 관리 모델을 제안한다. 특히, 제안 모델은 기존 망에서의 개선사항을 도출하고, 개선사항이 적용된 망을 설계하기 위해서 중앙 관리성을 향상시킨 실시간 보안 대응 능력, 보안 위협 발생 시 선제 탐지 및 능동적 대처, 중요 장비 이중활르 통한 고가용성, 고성능, 고신뢰성 확보, 개별 네트워크의 보안 정책 통합 관리, 개별 네트워크의 망 분리로 보안성 향성 등의 기능을 적용하였다.

복분자의 유방암 세포 사멸 및 사멸 유전자 발현 유도 효과 (Inducing Effects of Rubus coreanus on Cell Death and Apoptotic Gene Expressions in Human Breast Cancer Cells)

  • 김희정;강금지
    • 동아시아식생활학회지
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    • 제23권6호
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    • pp.723-732
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    • 2013
  • We investigated the inducing effects of Rubus coreanus extract (RCE) on apoptosis and its related gene expressions in human breast cancer cells. MDA-MB-231 cells were cultured in the presence of 0, 200, 300, and $400{\mu}g/mL$ RCE for 24h. MTT assay demonstrated that relative cell viability measured a decrease in a dose-dependent manner (p<0.05). This dependency was also found in the increasing levels of cell death by a dual staining with Hoechst 33322 and propidium iodide (p<0.05). These close associations was also observed by different stages of apoptotic processes, as shown by an Apoptosis Detection Kit. To determine whether the alterations in such cell activities obtained above cause the induction of apoptotic genes, PT-PCR was performed expressions of both Bcl-2 and Bax mRNAs. The Bcl-2/Bax ratio which is an important indicator of apoptosis, was found to have significantly decreased dose dependence (p<0.05). Western blot analysis also demonstrated that Caspase-3 significantly increases in a dose-dependent manner (p<0.05) in addition to similar alterations of other proteins examined. Taken these results together, the ethanolic RCE used induces a reduction in cell viability along with increased membrane permeability. This leads to a precautious apoptotic process and, subsequently, cell death through the apoptotic pathway involving Bax and Caspase-3 in human breast cancer MDA-MB-231 cells.

Interpretation of Dispersion Phenomena in Grunwald-Winstein Correlation for Solvolyses of Naphthoyl Chloride

  • Ryu, Zoon-Ha;Ju, Chang-Suk;Sung, Dae-Dong;Sung, Nak-Chang;Bentley, T. William
    • Bulletin of the Korean Chemical Society
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    • 제23권1호
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    • pp.123-131
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    • 2002
  • Solvolyses rate constant of 1- and 2- naphthoyl chlorides (1 and 2) are reported for aqueous binary mixtures with methanol, ethanol, fluorinated alcohol, acetonitrile and dioxane. Kinetic solvent isotope effects (KISE) in methanol and product selectivities (S) of 2-naphthoyl chloride (2) in alcohol-water are also reported. Dispersions in Grunwald-Winstein correlations $(r{\leq}0.901)$ are discussed by multiple regression analysis incorporating ionizing power $(Y_{Cl})$ scale and rate-rate profiles. Major causes for these phenomena are investigated as an aromatic ring solvation effects, in conjunction with weakly nucleophilic solvation effects ($S_N2$ character), for solvolyses of 1 and for solvolyses of 2, as dual reaction channels, described as $S_N1$-$S_N2$ and $S_AN$-$S_N2$ processes. Distinct border lines between the two pathways are derived from solvolyses rates of 2 in 18 solvent using the results of $log(k/k_o)=mY_{Cl}+lN_T+hI$ plot with values of 1.13 for m, 0.37 for l and 0.15 for h value in 5 aqueous fluorinated alcohol mixtures. Using rate-product correlation, the validity of a third order model based on a general base catalyzed by solvent and contribution from these rate constants, $k_{aa},\;k_{aw}$ and $k_{aw}$, are investigated for $S_AN$-$S_N2$ solvolyses of 2 favored in more rich alcohol media and gradual addition of water to alcohol solvent shows a great shift away from stoichiometric solvation to predominantly medium effects. Rate-rate correlation between solvolyses of 2 and trimethyl acetylchloride (5) with alkyl group in the 29 aqueous solvent mixtures shows appreciable linearity (slope = 0.84, r = 0.987), caused by the same pathway ($S_N1$-$S_N2$ process), even if this correlation coincides with appreciable dispersion (different solvation effect).

Tooth surface treatment strategies for adhesive cementation

  • Rohr, Nadja;Fischer, Jens
    • The Journal of Advanced Prosthodontics
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    • 제9권2호
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    • pp.85-92
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    • 2017
  • PURPOSE. The aim of this study was to evaluate the effect of tooth surface pre-treatment steps on shear bond strength, which is essential for understanding the adhesive cementation process. MATERIALS AND METHODS. Shear bond strengths of different cements with various tooth surface treatments (none, etching, priming, or etching and priming) on enamel and dentin of human teeth were measured using the Swiss shear test design. Three adhesives (Permaflo DC, Panavia F 2.0, and Panavia V5) and one self-adhesive cement (Panavia SA plus) were included in this study. The interface of the cement and the tooth surface with the different pre-treatments was analyzed using SEM. pH values of the cements and primers were measured. RESULTS. The highest bond strength values for all cements were achieved with etching and primer on enamel ($25.6{\pm}5.3-32.3{\pm}10.4MPa$). On dentin, etching and priming produced the highest bond strength values for all cements ($8.6{\pm}2.9-11.7{\pm}3.5MPa$) except for Panavia V5, which achieved significantly higher bond strengths when pre-treated with primer only ($15.3{\pm}4.1MPa$). Shear bond strength values were correlated with the micro-retentive surface topography of enamel and the tag length on dentin except for Panavia V5, which revealed the highest bond strength with primer application only without etching, resulting in short but sturdy tags. CONCLUSION. The highest bond strength can be achieved for Panavia F 2.0, Permaflo DC, and Panavia SA plus when the tooth substrate is previously etched and the respective primer is applied. The new cement Panavia V5 displayed low technique-sensitivity and attained significantly higher adhesion of all tested cements to dentin when only primer was applied.

Differentiation in Nitrogen-Converting Activity and Microbial Community Structure between Granular Size Fractions in a Continuous Autotrophic Nitrogen Removal Reactor

  • Qian, Feiyue;Chen, Xi;Wang, Jianfang;Shen, Yaoliang;Gao, Junjun;Mei, Juan
    • Journal of Microbiology and Biotechnology
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    • 제27권10호
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    • pp.1798-1807
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    • 2017
  • The differentiations in nitrogen-converting activity and microbial community structure between granular size fractions in a continuous completely autotrophic nitrogen removal over nitrite (CANON) reactor, having a superior specific nitrogen removal rate of $0.24g/(g\;VSS{\cdot}h)$, were investigated by batch tests and high-throughput pyrosequencing analysis, respectively. Results revealed that a high dissolved oxygen concentration (>1.8 mg/l) could result in efficient nitrite accumulation with small granules (0.2-0.6 mm in diameter), because aerobic ammonium-oxidizing bacteria (genus Nitrosomonas) predominated therein. Meanwhile, intermediate size granules (1.4-2.0 mm in diameter) showed the highest nitrogen removal activity of $40.4mg/(g\;VSS{\cdot}h)$ under sufficient oxygen supply, corresponding to the relative abundance ratio of aerobic to anaerobic ammonium-oxidizing bacteria (genus Candidatus Kuenenia) of 5.7. Additionally, a dual substrate competition for oxygen and nitrite would be considered as the main mechanism for repression of nitrite-oxidizing bacteria, and the few Nitrospira spp. did not remarkably affect the overall performance of the reactor. Because all the granular size fractions could accomplish the CANON process independently under oxygen limiting conditions, maintaining a diversity of granular size would facilitate the stability of the suspended growth CANON system.